Join restriction categories and the importance of being adhesive
Xiuzhan Guo · 2007
A category X is said to be adhesive if(i) X has pushouts along monics;(ii) X has pullbacks;(iii) pushouts along monics are van Kampen squares.Set and elementary toposes are adhesivebut Pos, Top, Grp, and Cat are not [4].We want to extend the notions of van Kampen squares andadhesive categories to van Kampen colimits and adhesiveM-categories ....